HIV epidemiology in the Northwestern Federal District of Russia: dominance of HIV type 1 subtype A.

A rapidly advancing epidemic of HIV-1 infection has been documented among injecting drug users (IDUs) in Russia. The Northwestern Federal District was the first of the seven Russian Federal Districts involved in a drug-related HIV epidemic through an outbreak in Kaliningrad in 1996. The Northwestern Federal District has a high HIV prevalence rate having reached 252 per 100,000 by the end of 2003, exceeding the Russian average (180) by 1.4 times. The epidemic peaked in 2001. Since then the annual number of new cases has decreased, probably reflecting saturation among at least some IDU populations. However, at the same time, the heterosexual spread of HIV has become more prominent. To study the genetic epidemiology of HIV-1, samples were collected from 150 individuals covering a wide geographical area and different transmission groups in the Northwestern Federal District. Phylogenetic analysis revealed that an Eastern European subtype A HIV-1 strain similar to those reported earlier among IDUs in other regions of Russia accounted for 80% of HIV-1 infections and was the predominant subtype in six out of seven administrative territories studied both among IDUs and heterosexually infected persons. As an exception to the dominant role of the Eastern European subtype A strain, the CRF03-AB strain was found to be dominant in the city of Cherepovets located in the north central European Russian territory of Vologda Oblast. This is the first report of the CRF03-AB strain causing an outbreak outside the Kaliningrad region.

HIV prevalence and risk behavior among injection drug users and their sex partners in two Russian cities.

The HIV epidemic in Russia remains concentrated mostly among injection drug users (IDUs). Little is known about the extent to which sexual partnerships are the bridge between IDUs and the general population and create the potential for generalizing the epidemic. IDUs in two Russian cities, Novosibirsk and Ivanovo (N=593), were recruited via respondent-driven sampling. A modified one-step snowball strategy was used to recruit IDU's sex partners who do not themselves use drugs (PIDU, N=82). Sexual behaviors of all participants were assessed using an interviewer-administered questionnaire. All participants provided blood specimens for HIV and hepatitis C virus (HCV) testing. HIV and HCV prevalence among IDUs was 34.0% and 44.4% in Ivanovo and 3.8% and 54.3% in Novosibirsk. HIV prevalence among PIDUs was 6.8% in Ivanovo and 8.7% in Novosibirsk. In both cities large proportions of IDUs reported sexual partnerships with non-IDUs-49.7% in Ivanovo vs. 62.7% in Novosibirsk (p≤0.001) and fewer than one in four IDUs reported constant condom use in such partnerships. This pilot study shows that two IDU populations with a significantly different HIV prevalence both form sexual partnerships with non-IDUs and practice unsafe sexual behavior within such types of partnerships. However, the proportion of PIDUs who form partnerships with other non-IDUs that therefore could lead to a generalization of the epidemic is very different between the two cities and this difference needs to be considered when estimating the spread of HIV into the general population. Unsafe sexual behavior and HIV testing should be specific targets for prevention activities for IDUs and their sex partners in Russia.

Individual-level, network-level and city-level factors associated with HIV prevalence among people who inject drugs in eight Russian cities: a cross-sectional study.

OBJECTIVES: To ascertain HIV prevalence among people who inject drug (injection drug users (IDUs)) in the Russian Federation and identify explanations for the disparity in different cities. DESIGN: Cross-sectional survey with serological testing for HIV and hepatitis C virus prevalent infections. SETTING: 8 Russian cities-Irkutsk, Omsk, Chelyabinsk, Yekaterinburg, Naberezhnye Chelny, Voronezh, Orel and St Petersburg. PARTICIPANTS: In 2007-2009 active IDUs were recruited by respondent-driven sampling with a target sample size of 300 or more in each city. MAIN OUTCOME MEASURES: Participants were administered a questionnaire covering sociodemographics, injection risk and protective behaviours, sexual behaviours, HIV knowledge, experiences with drug treatment and harm reduction programmes and social networks. Participants were tested for HIV and hepatitis C by enzyme immunoassay. Data were analysed to identify individual-level, network-level and city-level characteristics significantly associated with HIV prevalence. Factors significant at p≤0.1 were entered into a hierarchical regression model to control for multicollinearity. RESULTS: A total of 2596 active IDUs were recruited, interviewed and tested for HIV and hepatitis C virus infection. HIV prevalence ranged from 3% (in Voronezh) to 64% (in Yekaterinburg). Although individual-level and network-level variables explain some of the difference in prevalence across the eight cities, the over-riding variable that seems to account for most of the variance is the emergence of commercial, as opposed to homemade, heroin as the predominant form of opioid injected. CONCLUSIONS: The expansion of commercial heroin markets to many Russian cities may have served as a trigger for an expanding HIV epidemic among IDUs in that country.